The purpose of the Immunology Quality Assessment Program (IQA) is to continue and provide a resource to (1) evaluate the abilities of U.S. and non-U.S. laboratories to accurately and reliably perform study-specified immunological tests (with focus on CD4 and CD8 T cell lymphocyte counts and percentages) and viable PBMC freezing, (2) advise and train when deficiencies are identified, (3) evaluate immunology-based novel technologies (with focus on novel, simple tests for diagnosis and disease monitoring) for implementation in multi-site NIAID trials, and (4) maintain a computerized data management system and document library that include lab performance data and guidance documents. IQA will continue to support laboratories that are part of current and future NIAID-sponsored clinical trial networks